Naiture 6" x 10" Solid Brass Wall Register Wicker Style Chrome Finish Duct opening size: 6" x 10" (6-3/4" x 11-3/4" Overall) Made of heavy-duty solid cast brass for durability. Finished with a durable chrome powder coat finish to resist rust. Louver control extension from register: 3/4" which could control air flow easily by foot. Includes four wall springs for securing return into wall ducts. To determine size needed, measure air duct opening rather than old register or grille.